Radio jet refraction in galactic atmospheres with static pressure gradients

A theory of double radio sources which has a Z or S morphology is proposed, based on the refraction of radio jets in the extended atmosphere of an elliptical galaxy. The model describes a collimated jet of supersonic material bending self-consistently under the influence of external static pressure gradients. Gravity and magnetic fields are neglected in the simplest case except insofar as they determine the static pressure distribution. The calculation is a straightforward extension of the method used by Begelman, Rees, and Blandford to calculate a ram-pressure model for twin radio trails (C morphology). It may also be described as a continuous-jet version of the buoyancy model proposed by Gull and Northover